Systems and methods for voltage interfaces between legacy control systems and light sources

ABSTRACT

Examples of the present disclosure are related to systems and methods for voltage interfaces between legacy control systems and light sources. An example voltage interface may include a control loop including a first op-amp, an output loop including a second op-amp, and an optical isolator configured to electrically isolate the control loop from the output loop, the optical isolator being configured to receive an input signal from the control loop and transmit an output signal to the output loop.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims a benefit of priority under 35 U.S.C. § 119 toProvisional Application No. 62/596,890 filed on Dec. 10, 2017, which isfully incorporated herein by reference in their entirety.

BACKGROUND INFORMATION Field of the Disclosure

Examples of the present disclosure are related to systems and methodsfor voltage interfaces between legacy control systems and light sources.More specifically, implementations are directed towards a voltageinterface that is configured to output milliamps in a sinking orsourcing configuration to multiple outputs, wherein different channelsassociated with the voltage interface have isolated inputs and outputs.

Background

With the proliferation of LED lighting systems, controls for thelighting systems have become more important. Specifically, many lightingsystems implement dimmers to increase or decrease light intensity fromthe light sources. For example, in the greenhouse industry, lightsources must be dimmed for proper plant growth.

However, in industrial settings for different industries, differentmethods to control light dimming may conflict. This leads to unstable orsubstandard light dimming. In the greenhouse industry, often a 10 vpower source is used to control pumps, HVAC, LED lighting fixtures, andother systems. Yet, this voltage cannot be regulated or controlled whensupplied to the various elements. Further, in the greenhouse industry, acontroller generating the 10 v is typically a current source that isconnected to a high impedance load. The current that the controllersupplies is often less than 10 milliamps, and the controller typicallyonly sinks approximately 10 milliamps. However, elements in thegreenhouse industry typically require substantially higher current.

When coupling multiple light fixtures together with higher currents, thecircuits connected in parallel behave erratically. This leads to thelight fixtures developing current flow between the fixtures themselves,and also the controller. This leads to the circuits being shorted, whichruins the circuits.

Accordingly, needs exist for more effective and efficient systems andmethods for an interface with legacy control systems to be used withinLED fixtures.

SUMMARY

Implementations disclose systems and methods for voltage interfacesbetween legacy control systems and light sources. More specifically,implementations disclose a voltage interface that is configured toposition between a legacy control systems supplying 0 to 10 v and lightsources, wherein the interface is configured to control the currentsupplied to dim light fixtures. The elements within the voltageinterface may be configured to be electronically isolated from eachother using an optical isolator. By isolating the components theinterface, implementations may limit catastrophic failures bycontrolling situations in which voltage or current waves may betransmitted to the legacy control systems.

Implementations may include a legacy control system, light sources, andan interface.

The legacy control system may be a power source that is configured tosupply 0-10 volts to the interface. For example, the power source mayprovide zero volts to the interface in a sinking configuration, orprovide ten volts to the interface in a sourcing configuration. Thelegacy control system may be configured to supply the voltage andcurrent in DC.

The light sources may be an artificial light source that is configuredto stimulate plant growth by emitting light. For example, the lightsources may be LEDs. The light sources may be utilized to create lightor supplement natural light to the area of interest. The light sourcesmay provide a light spectrum that is similar to the sun, or provide aspectrum that is tailored to the needs of particular pants beingcultivated.

The interface may be configured to receive the voltage from the legacycontrol system, and output a voltage with a desired level of milliampsto the light sources, wherein the interface may operate in either asinking configuration or in a sourcing configuration. Inimplementations, the interface may be coupled with multiple inputsand/or outputs, wherein each of the inputs is isolated from each otherand each of the outputs is isolated from each other.

The interface may include a first op-amp and a second op-amp positionedin series, and an optical isolator positioned between the first op-ampand the second op-amp. The first op-amp may be configured to operate asa power device, and be a voltage follower, which has high inputimpedance and low output impedance. The first op-amp may be connected toa first power source having at least twelve volts and a first ground.

The second op-amp may a voltage follower amp, which is configured toreceive an input from the first op-amp, and output a voltage with a highcurrent, wherein the output current may be at least 750 milliamps. Insome implementations, the second op-amp may be connected to a secondpower source and a second ground. The second op-amp may be configured tohave multiple output channels, wherein each output channel mayindividually receive at least 750 milliamps. The channels may beconfigured to control different groups of light fixtures, wherein thelight sources on each channel may be independently controlled withdifferent dimming characteristics.

The optical isolator may include photo diodes that are configured toelectrically isolate the first op-amp from the second op-amp.

These, and other, aspects of the invention will be better appreciatedand understood when considered in conjunction with the followingdescription and the accompanying drawings. The following description,while indicating various implementations of the invention and numerousspecific details thereof, is given by way of illustration and not oflimitation. Many substitutions, modifications, additions orrearrangements may be made within the scope of the invention, and theinvention includes all such substitutions, modifications, additions orrearrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive implementations of the present inventionare described with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified.

FIG. 1 depicts a system for a voltage interface, according to animplementation.

FIG. 2 depicts a detailed view of an interface, according to animplementation.

FIG. 3 illustrates a method for utilizing an interface positionedbetween lighting sources and a legacy control system to control lightingcharacteristics of the lighting sources, according to an implementation.

Corresponding reference characters indicate corresponding componentsthroughout the several views of the drawings. Skilled artisans willappreciate that elements in the figures are illustrated for simplicityand clarity and have not necessarily been drawn to scale. For example,the dimensions of some of the elements in the figures may be exaggeratedrelative to other elements to help improve understanding of variousimplementations of the present disclosure. Also, common butwell-understood elements that are useful or necessary in a commerciallyfeasible implementation are often not depicted in order to facilitate aless obstructed view of these various implementations of the presentdisclosure.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the presentimplementations. It will be apparent, however, to one having ordinaryskill in the art that the specific detail need not be employed topractice the present implementations. In other instances, well-knownmaterials or methods have not been described in detail in order to avoidobscuring the present implementations.

FIG. 1 depicts a system 100 for a voltage interface, according to animplementation. As depicted in FIG. 1, system 100 may include a legacycontrol system 110, interface 120, and light sources 130.

Legacy control system 110 may be a power source that is configured tosupply 0-10 volts to the interface. For example, the legacy controlsystem 110 may provide zero volts to the interface in a sinkingconfiguration, or provide ten volts to the interface in a sourcingconfiguration. Legacy control system 110 may be configured to supply thevoltage and current in DC.

Interface 120 may include an input 112, and an output 114. Interface 120may be configured to output a higher current to light sources 130 on aplurality of different independent channels, which allows theindependent light sources 130 to be independently controlled. Interface120 may be configured to operate in either a sinking configuration or ina sourcing configuration. Input 112 may be configured to receive thevoltage from legacy control system 110. Output 114 may be configuredoutput a voltage with desired level of milliamps to the light sources130. In implementations, input 112 may be electrically isolated fromoutput 114. Output 114 may include a plurality of channels, which iseach configured to independently control a different light sourcegrouping. In implementations, the interface 120 may be coupled withmultiple inputs 112 and/or outputs 114, wherein each of the inputs 112and outputs 112 may be electronically isolated from each other usingdifferent power supplies and grounds. Interface 120 may also include anoptical isolator, which is configured to electronically isolate thefirst op-amp from the second op-amp.

Light sources 130 may be artificial light sources that are configured tostimulate plant growth by emitting light. For example, light sources 130may be LEDs. Light sources 130 may be utilized to create light orsupplement natural light to the area of interest. Light sources 130 mayprovide a light spectrum that is similar to the sun, or provide aspectrum that is tailored to the needs of particular pants beingcultivated. Implementations may include a plurality of different lightsources 130, which are individually grouped. The different groups oflight sources 130 may have different loads, and can also havecharacteristics that are independently controlled via interface 120.Additionally, the different groupings of light sources 130 may havedifferent numbers of LEDs, which may lead to the different groupings oflight sources 130 having different loads. The different groupings oflight sources 130 may each be connected to a different channel on output114. The channels may be configured to control different light source130 groups, wherein the light sources 130 on each channel may beindependently controlled with different dimming characteristics.

FIG. 2 depicts a detailed view of interface 120, according to animplementation.

As depicted in FIG. 2, interface 120 may include a control loop 210,isolator 220, and output loop 230.

Control loop 210 may include a first power source 202, a first ground204, first resistor 212, first op-amp 214, and first transistor 218.

First power source 202 may be configured to supply power to elementswithin control loop 210 and isolator 220. First power source 202 may beconfigured to be electrically isolated from elements within output loop230.

First ground 204 may be a reference point within first control loop 210where voltages are measured. Elements within control loop 210 may beelectrically coupled to first ground 204. However, elements withinoutput loop 230 may not be electrically coupled to first ground 204.

First resistor 212 may be configured to limit the voltage from legacycontrol system applied to op-amp 214.

First op-amp 214 may be configured to produce an output potential thatis greater than the potential difference between its input terminals.First op-amp 214 may be configured to receive power from first powersource 202, and be coupled to first ground 204.

First transistor 218 maybe configured to be coupled with isolator 220,first op-amp 214, and first ground 204 to form a servo-loop. The servoloop may be configured to accurately supply a desired voltage toisolator 220.

Isolator 220 may be a device that is configured to prevent unwantedfeedback from output loop 230 interacting with control loop 210.Isolator 220 may be configured to have inputs electrically isolated fromthe output of Isolator 220. In implementations, isolator 220 may be anoptical isolator, magnetic isolator, capacitive isolator, or any othertype of isolator that is configured to electronically separate a firstcircuit from a second circuit. Isolator 220 may include a secondresistor 222, first light emitting diode 224, first photo diode 226, andsecond photo diode 228.

Second resistor 222 may be a device that is configured to be coupledwith first power source 202 and first light emitting diode 224. Secondresistor 222 may be configured to limit a current applied to first lightemitting diode 224.

First light emitting diode 224 may be configured to transmit light,wherein the transmitted light may be measured by first photo diode 226and second photo diode 228. In implementations, first photo diode 226and second photo diode 228 may be the same components that areconfigured to similarly measure the light transmitted by first lightemitting diode 224.

First photo diode 226 may be utilized by first transistor 218 to formthe servo-loop. First photo diode 226 may be a closed control loop thatis formed along with first transistor 218. The closed control loopallows for a correlation between the voltage provided to the lightemitting diode 224 and the light intensity emitted by first lightemitting diode 224. This may allow the control loop 110 to regulate thelight emitted by first light emitting diode 224 to achieve a desiredintensity.

Second photo diode 228 may be configured to measure the light emitted bylight emitting diode 224, and to supply power to output loop 230.Further, second photo diode 228 is configured to operate as a lightbarrier between control loop 210 and output loop 230, which are notelectrically coupled together. In implementations, a voltage associatedwith the light measured by second photodiode 228 may be configured tooutput to output loop 230.

Output loop 230 may be configured to supply power to a series of lightfixtures, while also limiting current from impacting isolator 220.Output loop 230 may include a second power supply 232, a second ground234, second op-amp 240, and driver module 250.

Second power supply 232 may be configured to supply power to elementswithin output loop 230. Second power supply 232 may be configured to beelectrically isolated from elements within control loop 210.

Second ground 234 may be a reference point within output loop 230 wherevoltages are measured. Elements within second output loop 230 may beelectrically coupled to second ground 234. However, elements withinoutput loop 230 may not be electrically coupled to first ground 204.

Second op-amp 240 may be configured to operate as a buffer.Specifically, second op-amp 240 may be configured to amplify the signalfrom the isolator 220. In implementations, second op-amp 240 may utilizeresistors 242 positioned in series that are configured to be feedbackresistors. The feedback resistors 242 may be configured to calibrate theoutput of second op-amp 240 with the input applied to the first resistor212, such that voltage applied to first resistor 212 is similar to thatoutput from second op-amp 240. By controlling the voltage applied to thefirst resistor 212, implementations may be utilized to dim or control anintensity of light emitted from a plurality of light sources connectedto the output loop 230.

Driver module 250 may be an op-amp that is configured to output voltageswith very high current, such as one amp. The output with a very highcurrent may be utilized to drive a group of light fixtures. Inimplementations, the group of light fixtures may include up to fifty ormore light fixtures. Driver module 250 may be configured to be coupledwith second power supply 232 and second ground 234, while receiving aninput from second op-amp 240.

In further implementations, a plurality of output loops 230 may becoupled to isolator 220, wherein each of the output loops is associatedwith a different channel. Each of the plurality of output loops 230 mayhave isolated and independent grounds and power supplies.

FIG. 3 illustrates a method 300 for utilizing an interface positionedbetween lighting sources and a legacy control system to control lightingcharacteristics of the lighting sources, according to an implementation.The operations of method 300 presented below are intended to beillustrative. In some implementations, method 300 may be accomplishedwith one or more additional operations not described, and/or without oneor more of the operations discussed. Additionally, the order in whichthe operations of method 300 are illustrated in FIG. 3 and describedbelow is not intended to be limiting. The method 300 may be performed bya voltage interface, such as interface 120 in FIG. 1.

At operation 310, a control loop or control signal of the interface maybe configured to receive an input configured to adjust the lightingcharacteristics of lighting sources. The input may be received from alegacy control system, which may be a power source that supplies between0-10 volts. Electrical elements within the control loop may beconfigured to be coupled to a first power supply and a first ground.

At operation 320, an optical isolator is configured receive an inputfrom the control loop, and output a signal to an output loop. Theoptical isolator may form a light barrier between the control loop andan output loop, wherein the light barrier is configured to electricallyisolate elements within the control loop and elements within the outputloop. The output emitted from the optical isolator may be based on areceived signal powering a light emitting diode on a first side of thelight barrier, and a photodiode on a second side of the light barriermeasuring the emitted light.

At operation 330, the output loop may receive an input based on themeasurements of the photodiode on the second side of the light barrierin the optical isolator. In implementations, electrical elementspositioned within the output loop may be coupled to a second powersupply and a second ground, which are electrically isolated from thefirst power supply and the first ground.

At operation 340, a driver module may be configured may be configured toreceive an input signal from the output loop and power a plurality ofend-user devices, such as lighting fixtures. The output loop may includeone or more independent outputs, each output having a driver module thatis associated with a group of light sources, so that the output loop mayindependently control multiple groups of lights.

Although the present technology has been described in detail for thepurpose of illustration based on what is currently considered to be themost practical and preferred implementations, it is to be understoodthat such detail is solely for that purpose and that the technology isnot limited to the disclosed implementations, but, on the contrary, isintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the appended claims. For example, it isto be understood that the present technology contemplates that, to theextent possible, one or more features of any implementation can becombined with one or more features of any other implementation.

Reference throughout this specification to “one implementation”, “animplementation”, “one example” or “an example” means that a particularfeature, structure or characteristic described in connection with theimplementation or example is included in at least one implementation ofthe present invention. Thus, appearances of the phrases “in oneimplementation”, “in an implementation”, “one example” or “an example”in various places throughout this specification are not necessarily allreferring to the same implementation or example. Furthermore, theparticular features, structures or characteristics may be combined inany suitable combinations and/or sub-combinations in one or moreimplementations or examples. In addition, it is appreciated that thefigures provided herewith are for explanation purposes to personsordinarily skilled in the art and that the drawings are not necessarilydrawn to scale.

The flowcharts and block diagrams in the flow diagrams illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousimplementations of the present invention. In this regard, each block inthe flowcharts or block diagrams may represent a module, segment, orportion of code, which comprises one or more executable instructions forimplementing the specified logical function(s). It will also be notedthat each block of the block diagrams and/or flowchart illustrations,and combinations of blocks in the block diagrams and/or flowchartillustrations, may be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

What is claimed is:
 1. A system for controlling a plurality of lightfixtures, the system comprising: a control loop including a first op-ampconfigured to receive power from a first power source and to be coupledto a first ground; an output loop including a second op-amp configuredto receive power from a second power source and to be coupled to asecond ground, wherein the first power source and the second powersource are electrically isolated from each other and the first groundand the second ground are electrically isolated from each other; anoptical isolator configured to electrically isolate the control loopfrom the output loop, the optical isolator being configured to receivean input signal from the control loop and transmit an output signal tothe output loop.
 2. The system of claim 1, wherein the optical isolatoris configured to be coupled with the first power source and the firstground.
 3. The system of claim 1, wherein the optical isolator includesa light emitting diode, a first photodiode and a second photodiode, thelight emitting diode and the first photodiode being electrically coupledto the control loop, and the second photodiode being electricallycoupled to the output loop.
 4. The system of claim 3, wherein the firstphotodiode and the second photodiode are configured to measure an amountof light emitted by the light emitting diode.
 5. The system of claim 3,wherein the first photo diode is configured to form a closed controlloop with a first transistor.
 6. The system of claim 1, wherein theoutput loop includes one or more independent outputs, including a firstoutput electrically coupled to a driver module configured to output asignal with at least one amp of current.
 7. The system of claim 6,wherein the driver module is electrically coupled to the second powersource.
 8. The system of claim 6, wherein the driver module is coupledto a first group of light fixtures, and the driver module is configuredto output the signal to the group of light fixtures.
 9. The system ofclaim 1, wherein the first power supply and the second power supply areconfigured to supply a same voltage.
 10. The system of claim 1, whereinthe control loop is configured to receive an input from a power sourcethat supplies between zero and ten volts.
 11. A method for controlling aplurality of light fixtures, the method comprising: coupling firstelectrical elements within a control loop to a first power source and afirst ground, the control loop including a first op-amp; coupling secondelectrical elements within an output loop to a second power source and asecond ground, the output loop including a second op-amp, wherein thefirst power source and the second power source are electrically isolatedfrom each other and the first ground and the second ground areelectrically isolated from each other electrically isolating the controlloop and the output loop with an optical isolator, the optical isolatorbeing configured to receive an input signal from the control loop andtransmit an output signal to the output loop.
 12. The method of claim11, further comprising: coupling the optical isolator with the firstpower source and the first ground.
 13. The method of claim 11, whereinthe optical isolator includes a light emitting diode, a first photodiodeand a second photodiode, the light emitting diode and the firstphotodiode being electrically coupled to the control loop, and thesecond photodiode being electrically coupled to the output loop.
 14. Themethod of claim 13, further comprising: measuring, via the firstphotodiode and the second photodiode, an amount of light emitted by thelight emitting diode.
 15. The method of claim 13, further comprising:forming a closed control loop with the first photo diode and a firsttransistor.
 16. The method of claim 11, wherein the output loop includesone or more independent outputs, including a first output electricallycoupled to a driver module configured to output a signal with at leastone amp of current.
 17. The method of claim 16, further comprising:coupling the driver module to the second power source.
 18. The method ofclaim 16, further comprising: coupling the driver module to a firstgroup of light fixtures, and outputting the signal to the group of lightfixtures.
 19. The method of claim 11, wherein the first power supply andthe second power supply are configured to supply a same voltage.
 20. Themethod of claim 11, further comprising: receiving, by the control loop,an input from a power source that supplies between zero and ten volts.